The Port of Charleston is the second-busiest container port on the East Coast after New York. AP

The Port of Charleston has been evacuated early Thursday as federal authorities investigate a reported threat on a container ship that had arrived there from New York, according to reports.

The the port’s Wando Welch terminal was cleared out as the Coast Guard and FBI investigated the possible threat has had been described as an unconfirmed report of a “dirty bomb” on the ship, according to South Carolina’s WCSC-TV.

The commander of the local Coast Guard sector told Charleston’s WCIV that the unconfirmed claim was made by a YouTube “conspiracy theorist” but they were investigating out of an abundance of caution.

The vessel was reported as the Maersk Memphis, which docked around 8:30 p.m. Wednesday and traveled from New York.